Hi everyone.  I am curious to know if there is magnetometer in DJI's IMU. Because so far I can't find any article that tell IMU's DJI equipped with magnetometer (I am sorry if I missed the article that mention about this but for now I can't find it) . All article I found only mentioned about accelerometer, gyroscope, thermometer and barometer (with exception of article from wikipedia said IMU also possibly equipped with magnetometer).
Related to this question, may I know which sensor is effected by magnetic interference, compass or IMU?

Thank you

The compass is a magnetometer in effect. In the earlier P3 series, there was one compass, the P4 series has two compass units. They are not an integral part of the IMU, and are not located in the same place in the aircraft. The compass unit(s) are located in the bottom of the landing legs.

Geebax Posted at 2018-9-6 19:54
The compass is a magnetometer in effect. In the earlier P3 series, there was one compass, the P4 series has two compass units. They are not an integral part of the IMU, and are not located in the same place in the aircraft. The compass unit(s) are located in the bottom of the landing legs.

Thank you so much for your answer Geebax   I believe your answer indirectly tell there is no magnetometer in IMU.  If that case, it lead me to another question. What cause the IMU interference actually, since electromagnetic/magnetic force will only affect compass?  Thank you.

kayzex_ Posted at 2018-9-6 20:17
Thank you so much for your answer Geebax   I believe your answer indirectly tell there is no magnetometer in IMU.  If that case, it lead me to another question. What cause the IMU interference actually, since electromagnetic/magnetic force will only affect compass?  Thank you.

I've not heard of anything causing IMU interference.
Only magnetic interference of the compass and radio interference of the controller signal.

Labroides Posted at 2018-9-6 20:30
I've not heard of anything causing IMU interference.
Only magnetic interference of the compass and radio interference of the controller signal.

Thank you Labroides for your answer. It really help me Now i know DJI's IMU is only about attitude and movement and nothing to do with magnetism since it do not have magnetometer inside. Thank you again.  

The IMU in conjunction with GPS / Compass will pass orientation / attitude / acceleration / de-acceleration data to the Flight Controller. The IMU in effect is a junction of sensors.


The Flight Controller then has the job of combining all with the command inputs you make to create the flight requested.


If the Compass is affected by external influences - then its data will be outside of accepted limits and rejected by the IMU / FC. If you go to IMU page of GO - you will see the data boxes and how they are constantly changing …


There is no need for a Magnetometer in a DJi for simple reason we do not need to measure the magnetic force, we only need to know magnetic direction which a Magnetometer is not designed for.


Nigel

solentlife Posted at 2018-9-7 00:23
The IMU in conjunction with GPS / Compass will pass orientation / attitude / acceleration / de-acceleration data to the Flight Controller. The IMU in effect is a junction of sensors.

Thank you Captain Nigel. Now i have better understanding about magnetometer and IMU. I am totally a newbie in this area. Your explanation really help me. Thank you

kayzex_ Posted at 2018-9-7 01:12
Thank you Captain Nigel. Now i have better understanding about magnetometer and IMU. I am totally a newbie in this area. Your explanation really help me. Thank you

Hi, Glad to know about that. Thanks for the help of other co-pilots here in Forum. Should you have further question, please let us know. We are here to help. Thanks for choosing DJI. Have a great day.

DJI Natalia Posted at 2018-9-7 16:14
Hi, Glad to know about that. Thanks for the help of other co-pilots here in Forum. Should you have further question, please let us know. We are here to help. Thanks for choosing DJI. Have a great day.

Thank you Natalia. I will. Thank you very much

solentlife Posted at 2018-9-7 00:23
The IMU in conjunction with GPS / Compass will pass orientation / attitude / acceleration / de-acceleration data to the Flight Controller. The IMU in effect is a junction of sensors.

That’s interesting. Thanks for the info.